A major problem in neurobiology is how the central nervous system is able to coordinate the movements of different parts of the body during a behavior. The long-term objective of the proposed project is to help elucidate the mechanisms by which such coordination is achieved. Experiments will be carried out on the American cockroach. Insects will be pinned out in such a way that some of their legs will be free to move while intracellular recordings are taken from neurons impaled in the connectives which join two adjacent thoracic ganglia, or in the ganglia themselves. Detailed study will be made of neurons which respond preferentially to natural or imposed movement of one or more legs. This study will include morphological work with neurons filled with cobalt chloride or Lucifer yellow to determine the extent and location of dendritic and axonal arborizations. The morphological information will be used to help locate areas of synaptic interaction between the interneurons and sensory or motor neurons, so that the way sensory input influences motor output can be determined.